悪性食道狭窄に対する食道ステント留置術の長期成績と合併症

博士（医学）神戸大

Atomically Resolved Surface Structure of SrTiO3(001) Thin Films Grown in Step-Flow Mode by Pulsed Laser Deposition

The surface structure of SrTiO3(001) thin films homoepitaxially grown by PLD in step-flow mode was characterized using low temperature STM. It was found that one-dimensional (1D) TiOx-based nanostructures were formed on the thin film surface and their density increased with increasing thin film thickness. Most of the 1D nanostructures disappeared after a post-deposition annealing, indicating that this structure is metastable due to the nonequilibrium growth mode. The resulting surface after annealing exhibited similar features to that of a thinner film, having a domain structure with (2x1) and (1x2) reconstructions, but with fewer oxygen-vacancy-type defects. These results imply that the step-flow growth is likely to produce TiOx-rich surface and Ti deficiencies in the film. By the post-deposition annealing, the rich TiOx would diffuse from the surface into the film to compensate defects associated with Ti vacancies and oxygen vacancies, resulting in the stable surface structure with fewer oxygen vacancies. Thus, STM measurements can provide us with a microscopic picture of surface stoichiometry of thin films originating in the dynamics of the growth process, and can present a new approach for designing functional oxide films.Comment: 12 pages, 4 figure

Gate-electric-field and magnetic-field control of versatile topological phases in a semi-magnetic topological insulator

Surface states of a topological insulator demonstrate interesting quantum phenomena, such as the quantum anomalous Hall (QAH) effect and the quantum magnetoelectric effect. Fermi energy tuning plays a role in inducing phase transitions and developing future device functions. Here, we report on controlling the topological phases in a dual-gate field-effect transistor of a semi-magnetic topological insulator heterostructure. The heterostructure consists of magnetized one-surface and non-magnetic other-surface. By tuning the Fermi energy to the energy gap of the magnetized surface, the Hall conductivity $\sigma_{xy}$ becomes close to the half-integer quantized Hall conductivity $e^2/2h$, exemplifying parity anomaly. The dual-gate control enables the band structure alignment to the two quantum Hall states with $\sigma_{xy} = e^2/h$ and 0 under a strong magnetic field. These states are topologically equivalent to the QAH and axion insulator states, respectively. Precise and independent control of the band alignment of the top and bottom surfaces successively induces various topological phase transitions among the QAH, axion insulator, and parity anomaly states in magnetic topological insulators.Comment: 20 pages, 4 figure

Crystalline Inclusions in Hepatocyte Mitochondria of a Patient with Porphyria Cutanea Tarda

Intramitochondrial crystalline inclusions were found in hepatocytes of a patient with porphyria cutanea tarda (PCT). They were composed of parallel filamentous structures which measured approximately 12 nm in diameter. Each filament was separated from an adjacent filament by a space measuring approximately 5 nm. The mitochondria containing such inclusions were usually elongated and enlarged. It seemed likely that these changes are not particular in PCT, but indicate one reversible pathological finding in the liver

リュウシケイ オヨビ ソセイ オ セイギョ スル コト ニヨル ユビキタス ブッシツ ノ コウキノウカ : LaTiO2N ケイ サンチッカブツ ノ コウガク トクセイ ノ セイギョ

Some Perovskite-type LaTiO2+xN1-x with anion nonstoichiometry were prepared by heating an oxide precursor under ammonia atmosphere and successively annealed under diluted ammonia. Increasing O/N ratio enhances the optical bandgap of the oxynitrides. A series of perovskite-type LaTiO2N materials with compositions a slightly deviated from the stoichiometric metal composition was also prepared. Increasing Ti/La ratio in La1-xTi1+xTiO2N results in deterioration of reflectivity in the longer wavelength region above the absorption edge. A substitution of La by Sr was effective in the enhancement of reflectivity there. Though the increase of O/N ratio in the LaTiO2+xN1-x series was found to cause oxidation of titanium by means of XPS spectroscopy, the valence state of titanium did not change in either the La1-xTi1+xO2N or the La1-xSrxTiO2N series. The increase in Ti/La ratio in the La1-xTi1+xO2N brought the grain/particle growth, which seemed to result in the deterioration of reflectivity

過疎化集落の児童に対するレジリエンスを育む取り組み

我が国では、平成10 年に自殺者数が3万人を超えて以来、14年連続して3万人を超える状況が続いていた。現在、3年連続で自殺者数は3万人を下回っているが、いまだその数は多いものであり、早期からの自殺予防が重要視されている。そこで、本稿では奈良県の自殺対策事業モデル地区である下北山村で実施された寺子屋事業について報告するものである。本事業は学童期の子どもたちを対象に、早期からの自殺予防という観点から行われた自殺対策事業であり、“こころのふるさと”を育み、レジリエンスを向上させることで、将来的な自殺予防へ繋げることを目的としていた。さまざまな活動を通して子どもたちそれぞれに“こころのふるさと”は形成され、レジリエンスは高められたと思われた